1. Field of the Invention
The present invention relates to an electromagnetic clutch used in a vehicle.
2. Related Art
JP-A-2000-240684 discloses a connection device including a main clutch that is operated by an electromagnet to connect a housing with a hub. In the connection device, the housing includes a rear housing and a front housing, and the rear housing is screw-connected to the front housing. When the electromagnet is energized, magnetic lines pass through the front housing to fasten an electromagnetic pilot clutch and to fasten the main clutch, thereby connecting the housing to the hub.
However, in the connection device, the electromagnet is disposed in the inner periphery of the rear housing. Additionally, the connection portion where the rear housing is screw-connected to the front housing is disposed in the outer periphery of a core of the electromagnet. For these reasons, each member protrudes in the radial direction at a position where the electromagnet is disposed, thereby causing an increase in size of the connection device in the radial direction.